Accepted for Publication: July 24, 2013.
Published Online: January 22, 2014. doi:10.1001/jamasurg.2013.4834.
Study concept and design: Matsushima, Won, Indeck, Soybel.
Acquisition of data: Matsushima, Won.
Analysis and interpretation of data: Matsushima, Schaefer, Won, Armen, Soybel.
Drafting of the manuscript: Matsushima, Won, Soybel.
Critical revision of the manuscript for important intellectual content: Matsushima, Schaefer, Armen, Indeck, Soybel.
Statistical analysis: Matsushima, Schaefer.
Obtained funding: Matsushima.
Administrative, technical, and material support: Armen, Soybel.
Study supervision: Armen, Indeck, Soybel.
Conflict of Interest Disclosures: None reported.
Additional Contributions: The data used in this study were provided by the Pennsylvania Trauma Systems Foundation, Mechanicsburg, Pennsylvania. The foundation specifically disclaims responsibility for any analyses, interpretations, or conclusions. The Pennsylvania Trauma Outcome Study (PTOS) was the source of the data.